The present invention relates generally to disc drive systems, and particularly but not by limitation to disc head sliders within disc drive systems.
In data processing systems, disc drives are often used as storage devices. Such drives use rigid discs, which are coated with a magnetizable medium for storage of digital information in a plurality of circular, concentric data tracks. The discs are mounted on a spindle motor, which causes the discs to spin and the surfaces of the discs to pass under respective hydrodynamic (e.g. air) bearing disc head sliders. The sliders carry transducers, which write information to and read information from the disc surfaces.
An actuator mechanism moves the sliders from track-to-track across the surfaces of the discs under control of electronic circuitry. The actuator mechanism includes a track accessing arm and a suspension for each slider assembly. The suspension includes a load beam and a gimbal. The load beam provides a load force that forces the slider toward the disc surface. The gimbal is positioned between the slider and the load beam, or is integrated in the load beam, to provide a resilient connection that allows the slider to pitch and roll while following the topography of the disc.
The slider includes a bearing surface, which faces the disc surface. As the disc rotates, the disc drags air under the slider and along the bearing surface in a direction approximately parallel to the tangential velocity of the disc. As the air passes beneath the bearing surface, air compression along the air flow path causes the air pressure between the disc and the bearing surface to increase, which creates a hydrodynamic lifting force that counteracts the load force and causes the slider to lift and fly above or in close proximity to the disc surface.
One type of slider is a xe2x80x9cself-loadingxe2x80x9d air bearing slider, which includes a leading taper (or stepped-taper), a pair of raised side rails, a cavity dam and a sub-ambient pressure cavity. The leading taper is typically lapped or etched onto the end of the slider that is opposite to the recording head. The leading taper pressurizes the air as the air is dragged under the slider by the disc surface. An additional effect of the leading taper is that the pressure distribution under the slider has a first peak near the taper end or xe2x80x9cleading edgexe2x80x9d due to a high compression angle of the taper or step, and a second peak near the recording end or xe2x80x9ctrailing edgexe2x80x9d enabling a low bearing clearance for efficient magnetic recording.
The slider typically possess three degrees of freedom (vertical motion, pitch rotation and roll rotation) associated with three applied forces, e.g., pre-load forces and air bearing suction and lift forces. Steady state fly attitude of the entire slider is achieved when these three forces balance each other. Desirably, the fluid bearing underneath the slider maintains a steady state position relative to the media and possesses intrinsic stiffness with respect to its three degrees of freedom, e.g., vertical stiffness, pitch stiffness and roll stiffness.
The bearing clearance between the slider and the disc surface at the recording height is an important parameter to disc drive performance. Efforts have been made to design sliders having specialized features on the disc-facing surface that enable the slider to operate at particularly low fly heights. As slider designs evolve and average flying heights continue to be reduced, contamination particles have been observed to become an increasing source of head modulation leading, in some cases, to read/write failures. Many low fly height slider designs have been observed to disadvantageously encourage an accumulation of contamination particles in the transducer region of the slider. Particles that linger in the transducer region of the slider can lead to irrecoverable data loss.
Embodiments of the present invention provide solutions to these and other problems, and offer advantages over the prior art are.
The present invention relates to data storage devices that include disc head sliders having disc-facing surface configurations that address the above-mentioned problems.
One embodiment of the present invention pertains to a disc head slider that includes a disc-facing surface. The disc-facing surface comprises an inside set of surface components that includes an inside cavity dam and an inside sub-ambient pressure cavity having an inside cavity floor. The disc-facing surface further comprises an outside set of surface components that includes an outside cavity dam and an outside sub-ambient pressure cavity having an outside cavity floor. The disc-facing surface also comprises a center set of surface components that is generally disposed between the inside and outside sets of surface components. The center set of surface components includes a center cavity dam and a center sub-ambient pressure cavity having a center cavity floor. The inside, outside and center sets of surface components are separate and disassociated from one another.
Another embodiment of the present invention pertains to a disc head slider comprising a disc-facing surface having a peripheral edge. The peripheral edge includes a leading edge, a trailing edge and side edges joining the leading edge and the trailing edge. The disc-facing surface further comprises a first set of surface components that includes a first cavity dam and a first sub-ambient pressure cavity having a first cavity floor. The disc-facing surface also comprises a second set of surface components that includes a second cavity dam and a second sub-ambient pressure cavity having a second cavity floor. The first set of surface components is positioned between the second set of surface components and a side edge. The disc-facing surface further comprises a leading surface component generally positioned between the leading edge and the first set of surface components. A plurality of recessed surfaces generally surround the first set of surface components and separate the first set of surfaces components from the second set of surface components, the leading surface component, the trailing edge and the side edge.
Yet another embodiment pertains to a disc drive that includes a disc rotatable about a central axis. The disc has a recording surface. The disc drive also includes disc head slider means for carrying a transducer at a fly height relative to the recording surface during rotation of the disc and for affecting mass flow during rotation of the disc.
Still another embodiment pertains to a disc head slider having a disc-facing surface. The disc-facing surface includes a cavity dam and a sub-ambient pressure cavity having a cavity floor. The disc-facing surface also includes an inside rail disposed on a first side of the sub-ambient pressure cavity, and an outside rail disposed on a second side of the sub-ambient pressure cavity. The disc-facing surface also includes a center pad having a step surface and a bearing surface. A xe2x80x9cYxe2x80x9d shaped channel is formed in the bearing surface.
Other features and benefits that characterize embodiments of the present invention will be apparent upon a reading of the following detailed description and review of the associated drawings.